1. Field of the Disclosure
The disclosure relates to a touch apparatus and a touch method, and more particularly, relates to an optical touch apparatus and an optical touch method.
2. Description of Related Art
Recently, touch electronic products have become very popular among consumers due to the easy operation and high intuition thereof, and have gradually become mainstream in the market. Among the resistive, capacitive, and rear projection touch screens used in the past, the capacitive touch screen has the best touch effect. However, the capacitive touch screen is also the most expensive, and the cost thereof increases with larger screen size, thereby limiting the application of the capacitive touch screen. To find an alternative to the capacitive touch screen, an optical touch technology using an optical sensing module to detect a touch position is currently available. The optical touch technology has the advantages of low cost and good accuracy, and is more advantageous in the competitive market. As a result, the optical touch technology has currently also become an alternative for a large-size touch screen.
Generally speaking, in the optical touch technology, a light source module and the optical sensing module are disposed on edges of the screen, and the touch light source is guided to a touch area through a light guide member of the light source module. A determination is made according a touching feature generated by the optical sensing module according to a part of light from the touch light source being reflected or blocked by a touching object, such that a position where the touching object is located may then be calculated.
However, when a quantity of the touching objects is greater than two, it is more complex for a processing unit to identify and calculate the touch positions. Further, misjudgments or interrupts may also be generated due to conditions such as a “ghost points” issue, which also needs to be solved. For instance, when two touching objects touch the touch area at the same time, as an effect of cross-capturing images by the optical sensing module, four intersection points including two touch points and two ghost points are generated. At the time, the processing unit may calculate coordinates of the two touch points and coordinates of the two ghost points; confirm that the two touch points are the real touch points after identifying based on determination and selection regarding specific features and conditions; and then only output the coordinates of the two points being confirmed. A quantity of the ghost points gets more when the quantity of the touching objects is more. For instance, in case the quantity of the touching object is three, as the effect of cross-capturing images by the optical sensing module, nine intersection points are generated, in which the quantity of the ghost points is six. In other words, as the quantity of the touching objects gets more, the determination for the ghost points is more complex, so that amount of calculations is also increased.
In addition, in order to achieve a purpose of multi-touch, a solution is to increase a of sensors on different positions of the touch area as to facilitate in determining the ghost points and filtering the ghost points to determine the real touch points. Nevertheless, product cost may be increased accordingly, and a lot of time is still wasted because the amount of the calculations is overly high.